Overwriting an anim sequence may scale the play rate of the anim instead of modifying underlying frame rate

The frame rate for an anim sequence is not being changed as expected when its being overwritten / re-imported.

Steps to Reproduce

1. Bake an anim sequence from a level sequence that targets 24 fps
2. Create a montage from that anim sequence - now the montage will be set to 24 fps
3. Bake another anim sequence from the same level seqeuence, but overwrite the aforementioned one with it. That anim should target 30 fps.
4. Notice how the fps doesn't change on that exported anim, but instead the play rate is scaled - this is the bug!